As reported by gameindustry.biz, Boston development studio Harmonix has ended their co-partnership agreement with publisher Mad Catz’ after reports of poor Rock Band 4 sales.

The co-partnership agreement was formed in April 2015 in anticipation of Rock Band 4. The game was well received by critics but had sold poorly during its launch in October. The game’s development costs and poor sales resulted in Mad Catz losing their profit from last fiscal year, negatively influencing their $4.7 million profit by 345% – leaving them with an $11.6 million loss.

Mad Catz has also been charged $6.8 million to cover inventory write-downs of copies of Rock Band 4 and price reductions with retailers. Harmonix had confessed to creating fake Amazon reviews of their game shortly after its launch in October. The Boston-based studio has since terminated their co-publishing agreement with Mad Catz.

“Rock Band sell-through was lower than originally forecast resulting in higher inventory balances as well as lower margins due to increased promotional activity with retailers”, said Mad Catz CEO, Karen McGinnis.

“The overall Rock Band 4 program was incredibly disappointing for us. Exiting the relationship with Harmonix at this time allows us to focus our efforts on the development and execution of our other exciting and profitable product launches.”